Today it is the 50th anniversary of the first launch using the three stage Proton-K with the Blok D fourth stage added for deep space missions. The payload was Cosmos 146, the first test of the Soyuz-derived L-1 spacecraft which was designed to carry two cosmonauts around the Moon (in reality, none of the missions carried a human crew).

As well as becoming the mainstay for launching the Soviet unmanned deep space (Moon, Mars and Venus) exploration programmes with the Blok D, the Proton-K with a modified Blok DM stage was introduced in 1974 and that became the launch vehicle of choice for Soviet satellites intended to go to geosynchronous orbit.

In June this year one of the papers I am presenting at the British Interplanetary Society conference will be reviewing flights using the Blok D/DM family of upper stages.

Philip: Is the BIS still publishing a special issue dealing with the Soviet/Russian/CIS papers presented to it's special gatherings?

Yes they are. The papers are mainly published in an issue of JBIS/Space Chronicle. I have recently had the proofs of two papers that are scheduled for the next one, possibly around June when there's the next meeting. They are trying to decide what to do with my paper on photoreconnaissance satellites because it's so long! - maybe split it over two issues of theregular JBIS.

On the Russianspaceweb page there is a nice image of the SOZ units separating from the Blok-D. However, the image also shows the frontal cone of L1 still attached. Comments here have indicated that the function of the cone was as interface between the Descent Module and the Launch Escape System, and that the cone would jettisoned as soon as practical after the LES was jettisoned. Therefore, the cone not still be attached that late in the mission.